Self-cleaning air-screen valve.



PATENTED NOVl 2l, 1905. W. T. SEARS.

SELLl CLEANING AIR SCREEN VALVE. APPLICATION FILED PBB.18.1905.

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No. 805,237, PATENTED NOV. 2l, 1905. W. T. SEARS.

SELF CLEANING AIR SCREEN VALVE.

APPLICATION FILED FBB.18.1905.

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SELF-CLEANING AIR-SCREEN VALVE.

Specification of Letters Patent.

Patented Nov. 21, 1905.

Application filed February 18, 1905. Serial No. 246.209.

To all whom it may concern:

Be it known that I, WILLARD T. SEARS, a citizen of the United States,residingin Harrisburg, Pennsylvania, have invented certain Improvementsin Self Cleaning Air Screen Valves, of which the following is aspecification.

My invention consists of a novel structure, including a screen and avalve therefor, whereby the direction of flow of the fluid through thescreen may be reversed at will, and thereby caused to remove particlesof foreign matter which have lodged upon the screen, dison the line 2 2,Fig. l, and respectively illus-` trating the screen in its normalposition and in the position which it occupies while being cleaned, thevalve in this device being of the plug type. Figs. 4 and 5 are verticalsections of another form of myinvention in which the valve for changingthe direction of flow of current ofthe iiuid is of the sliding'cylindrical type, the screen being stationary. Figs. 6 and V7 illustrateaform of my invention in which,

as in the construction shown in Figs. 4 and 5, the valve is of thesliding type, though the screen moves with the valve. are horizontalsections of another form of my invention in which the screen isstationary and the direction of iiow of fluid through said screen iscontrolled by two plug-valves. Fig. 10 is a vertical section of myinvention, showing it as constructed in a form not unlike that of theordinary engine slide-valve, the screen being stationary. Fig. l1 is avertical section of a form of the invention in which the screen isstationary,the valve having through it three passages so placed that byturning the valve through a smallangle the direction of the flow ofair-current through the screen may be reversed. Fig. 12 is a verticalsection of aform of my invention in which the screen is carried by achambered slide-valve; and Fig. 13 is another form of my device somewhatsimilar Figs. 8 and 9' to that shown in Figs. 1 to 3, inclusive, butdiering therefrom in having an auxiliary airpassage formed in the valveinstead of in the valve casing or conduit.

Referring to Figs. l to 3, inclusive, A represents a portion of aconduit or conductor for Huid under pressure, such as air or gas, havingan enlarged portion, as shown, provided with a chamber in which operatesa plug-valve B. In the present instance this valve is substantiallyconical in form and has a cap or cover b threaded into a suitable recessof the casing a. Said valve may be turned on its axis by-means of asquare-ended spindle b and is also provided with a screen C, held in anydesired manner within it and interposed between two openings b2 and 3 inits sides. By an inspection of Figs. 2 and 3 it will be seen that thecasing c, in addition to the through or straight passage-way a in theline in which the valve B is interposed. is provided with a secondpassage a2, connecting one portion of the passage a with the chambercontaining said valve at a point preferably ninety degrees distant frornthe point at which said passage @"enters. There is also an opening@3 inthe Wall of the casing (t, opposite the point of entrance of the passagece into the valve-chamber, connecting the interior of said casing withthe atmosphere. As

will be seen from Fig. 2, under ordinary working conditions air, gas, orother fluid is free to flow through the passage c in the directionindicated by the arrow it being necessary for said fluid to pass throughthe valve B and the screen C, so that any objectionable pieces of solidmaterial are caught. IVhenever desired, the valve B may be turned to theposition shown inFig. 3, so as to place the two openings 62 and b3 inline with the end of the passage a2 and the opening e3, it beingunderstood that in doing this the valve is turned in the directionindicated by the arrow y. Under these conditions pieces of solidmaterial which have found lodgment upon the screen C or within thecavity of the valve B are forcibly blown out of the opening a3, afterwhich the valve may be returned to its normal position. A

In the form of the invention shown in Figs. 8 and 9 I have provided twovalves B and B2, placing them in suitable chambers in a casing A' andproviding them with passages opening at points upon their surfacesninetyT degrees distant from each other. Suitable passage-ways areconstructed to coact with the Sio IOO

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openings through the valves, and a screen C is interposed in an enlargedcavity between the valves. The valve Bhas opening into its chamber thepassage or chamber containing the screen C, the air-supply passage a',and the passage a2, communicating with the atmosphere, while the valveB2 communicates with the screen-chamber and with both ends ofthe passagea'. Under normal operating conditions fluid passes from passage a'through valve B, as shown in Fig. 8, through screen C, and valve B2.iVhen, however, it is desired to clean the screen, the valves are turnedinto the position shown in Fig. 9, when the iiuid passes from passage athrough valve B2, screen C, valve B, and passage a2 into the atmosphere.

1n Figs. 4c and 5 there is but a single valve B3, and this is of thesliding type. The main conduit A2 is provided with two partitions ce2,between which the screen C is interposed. The movable portion of thestructure, which is of cylindrical form, is constructed to slide uponsaid conduit A2 and is provided with two annular chambers ZJ* and b2, aswell as with two annular ports. One oi' these, 62, communicates with theatmosphere, while the second, communicates with the annular chamber b4through suitable sets of ports a2 to a, inclusive, extending through thewalls of theconduit A2, these sets being respectively arranged in planesat right angles to the line of said conduit. With the valve in theposition shown in Fig. 4 fluid entering in the direction of the arrowpasses through ports a2 into chamber t* of the valve B2, through ports ainto the interior of the conduit, through the screen C, ports as,chamber 2, and ports a into the cond uit again, the foreign materialbeing, as before, caught on the screen C. When, however, the valve B3 ismoved into the position shown in Fig. 5, the fluid passing through portsa2 into the chamber a2 is forced to iow through the passagesinto theports 52 and so into the interior of the conduit, subsequently passingthrough the screen in a direction the reverse of that existing undernormal conditions through opening' a and ports b2 into the atmosphere.ln this instance the screen C is stationary; but if it be desired thatthis shall move with the valve structure independently of the conduitthis may be accomplished by the construction shown in Figs. 6 and 7. Asbefore, the valve slides upon the outside of the conduit A3 and haswithin it but a single annular chamber, which, however, opens onto theinterior surface of the valve at its ends through passages Z1 and b2.The screen C is, however, interposed in the valve-chamber between saidtwo sets of openings, it being noted that the latter of these iselongated, while the conduit structure A3 is provided with a portion @loof less diameter than the remainder, so that when the valve B2 is movedinto one of its extreme positions the openings b2 connect the interiorof the valve-chamber with the atmosphere. There are two sets of ports auand (L12, opening through the walls of the conduit A2, and a partitiona, extending across said conduit between said sets of openings or ports.Tith this arrangement of parts fluid moving in the conduit i`n thedirection of the arrow in Fig. 6 is forced to ow through ports 412thereof, port b2 of the valve into the valvechamber, and through screenC, passing from thence through openings b2, ports a, back into theconduit. When, however, it is desired to clean the screen, the valve ismoved into the position shown in Fig. 7, so that the air passing throughports @22 enters the ports bs of the valve, and after passing throughthe screen flows through the port L2 to the atmosphere, carrying with itwhatever i'oreign'material may have lodged upon the screen C.

In that form of the invention illustrated in Fig. l() l have shown avalve B2 in its midposition, so that the flow of air is cut off.However, if this valve be moved to the left the airiiow takes placethrough a central port d of said valve through a cavity D in thestructure to which the device is applied through the screen C, port d inthe valve, and out the air-channel a. Moving the valve B to the right asuiicient distance places its port Z in communication with the secondopening of the cavity'D, so that flow or' air takes place through thescreen C in a direction the reverse of that previously existing, such owpassing through port (Z2 of the valve to the atmosphere by way of thechannel a3 in the supporting structure. Fig. ll illustrates a somewhatsimilar arrangement oan-conducting passages in the fixed structure towhich my invention is applied, though in this case the valve B6 is ofthe rotary instead of the sliding type. By turning it through arelatively small angle in the direction indicated by the arrow Lc theair-currententering through the passage a is reversed as to itsdirection of travel through the screen C, and the solid particles lodgedagainst said `screen are discharged through the passage a3.

In the construction shown by both the two last-mentioned iigures thescreen is stationary; but in the modification shown in Fig. l2 it iscarried by the sliding-valve structure B2, which is provided withpassages cooperating with four passages, each two of which open onopposite sides of the structure surrounding the valve. As previouslydescribed in connection with the other forms .of my device, the movementof the valve from the position shown through a relatively small distanceto the right causes the air-current to be cut otf from its exit-passagea and after causing it to pass through the screen C in a direction thereverse of its normal flow permits it to discharge particles of foreignmatter lodged upon the screen through the passage a2.

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The form of my invention shown in Fig. 13 operates in a manner identicalwith that described in connection with Figs. l to 3, inclusive, though Ihave modified the construction, so that where in th'e three firstdescribed ligures the auxiliary passage a2 is formed in the valve casingin this instance such passage is formedy in the valve itself, asindicated at a, it being noted that in the illustration the valve isshown in a position in which the iiow of air takes place through thescreen in a direction to remove the particles of foreign mattertherefrom.

I claim as my invention- 1. The combination of a conduit, a movablestructure, and a screen carried by said structure independent of thewalls thereof, there being an inlet and two outlets so arranged thatwhen the movable structure is in one position, fluid in the conduitpasses from the inlet in one direction through the screen to one of theoutlets, and when said structure is in a second position said Huidpasses through the screen in an opposite direction to the second outlet,substantially as described.

2. rIhe combination of a conduit having main and auxiliary passages, avalve, and a screen carried within said valve transverse to the passagetherethrough and independent of the outer walls thereof, the valve beingmovable to direct fluid either through the screen and the main passage,or through the screen in a reversed direction and through the auxiliarypassage, substantially as described.

3. The combination of a conduit having a main passage and an auxiliarypassage including a discharge-opening, a valve for the conduit, and ascreen carried hy the valve and in addition to the wall structurethereof, the valve being movable to direct` iiuid either through thescreen and the main passage, or through the auxiliary` passage, throughthe screen in a reverse direction and the dischargeopening,substantially as described.

4;. vThe combination of a conduit having main and auxiliary passages, avalve for said conduit having a through-passage and a substantiallyplane screen transverse thereto, said valve being movable to direct uideither i ally independent of the wall structures of said valve, thevalve being constructed to either cause How of uid through the screenand the conduit in one direction, or flow from the conduit through thescreen in a reverse direction, to a discharge-opening independent of themain outlet, substantially as described.

6. The combination of aconduit having main and auxiliary passages, therebeing also an opening for waste, a valve in the conduithaving mounted init a plane screen, said valve being movable so as to permit flow offluid through the conduit, or from the conduit to the waste-opening, thedirection of such flow through the screen being reversed in said twocases, substantially as described.

7. The combination of a casing havinga main passage including a chamber.a valve in the chamberhavingathrough-passage and ascreen therein, therebeing an auxiliary passage from the conduit to said chamber and awaste-passage from the chamber, said valve being mov- 'able to connecteither the two sections of the main passage, or the auxiliary and thewaste passages, substantially as described.

8. The combination of a conduit having main and auxiliary passages,there being also an opening for waste, a revoluble valve in the conduitcarrying a screen, said valve being movable so as to permit flow of Huidthrough the conduit or from the conduit through the auxiliary passagethrough the screen to the waste opening, the direction of such flowthrough the screen being reversed. in said two cases, substantially asdescribed.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

VILLARD T. SEARS.

Witnesses:

WM. E. SHUPE, Jos. H. KLEIN.

